With the recent tendency toward westernized eating habits in Japan, intake of high fat diet continues to increase. According to a National Nutrition Survey in Japan (1999), among people over 60, it is reported that although their energy intake is decreasing every year, their fat energy ratio exceeds the reasonable proportion of 25%, and 50 to 60% of those people are recognized to have high triglyceride and cholesterol values [Summary of 1999 National Nutrition Survey in Japan by The Ministry of Health, Labor and Welfare, Rinsho Eiyo (Clinical nutrition) 2001; 98(5): 577-588].
Obesity is one of the most severe diseases in present day society, caused by excessive fat intake. Excessive fat intake causes not only obesity, but also contracting disorders such as diabetes, hyperlipidemia, hypertension and arteriosclerosis. In Japan, Mazindole (registered trademark), an anorectic drug, is only one therapeutic drug with official approval for treating obesity. However, this drug is reported to have side effects such as excessive thirst (mouth dryness), constipation, epigastric distress, nausea and vomiting [Rinsyo Hyouka (Clinical evaluation), 1985; 13(2): 419-459, Clinical evaluation, 1985; 13(2): 461-515]. Overseas, Xenical (registered trademark) as a lipase inhibitor which suppresses fat absorption in the gastrointestinal tract, is on market as an obesity treatment drug. However, this drug is also reported to have side effects such as fatty stool, increased stool frequency, soft stool, diarrhea and stomachache. Therefore, using this drug is sometimes accompanied by concerns about safety (Lancet 1998; 352:67-172)
To prevent obesity, it is advantageous to reduce the caloric intake by controlling diet. However, it requires careful guidance on nutrition, making it difficult to practice in daily life. Therefore, inhibiting absorption of dietary lipids in the body in a safe and healthy manner is practical and useful for treatment of obesity and related diseases and in promoting health.
With these facts in mind, the development of “food for specified health uses” which is safe to use and is proven to be effective in treating humans is attracting a lot of attention. Food materials which inhibit increase of serum triglycerides after a meal, such as: a globin protein decomposition product that suppresses fat absorption by pancreatic lipase inhibitory activity [J. Nutr. 1988; 128: 56-60, Nihon Eiyou Shokuryou Gakkai-shi (Journal of Japanese society of Nutrition and Food Science) 1999; 52(2): 71-77, Kenkou Eiyou Shokuhin Kenkyu (Health food and nutrition food Research) 2002; 5(3): 131-144]; diacylglycerol with different digestion and absorption features compared to triacylglycerol (J. Am. Coll. Nutr. 2000; 19(6): 789-796, Clin. Chim. Acta. 2001; 11(2): 109-117); eicosapentaenoic acid (EPA) and docosahexanoic acid (DHA) purified from fish oil; are on market as foods for specified health use until now.
Lipase inhibitors derived from plants are also attracting attention in recent years. Especially, as to the polyphenols with lipase inhibitory activity, for example: tannin from bark (JP Shou 60-11912-B); tannins, flavonoids and glucosides thereof from leguminous plant (Cassia mimosoides L.var.nomame Makino) (JP Hei 8-259557-A); epigallocatechin gallate which is the main component in green tea, and lipid-absorption-suppressing food containing the epigallocatechin gallate (JP Hei 3-228664-A); lipase inhibitory agent containing water extracts from green pepper, shimeji mushrooms, pumpkin, Grifola frondosa (maitake), Hizikia fusiforme, green tea, oolong tea, and others (JP Hei 3-219872-A); flavons and flavonols (JP Hei 7-61927-A); hydroxybenzoic acids (gallic acid) (JP Hei 1-102022-A); triterpenes and derivatives thereof (JP Hei 9-40689-A); and anti-obesity medicine containing procyanidin from Tamarind as an active ingredient (JP Hei 9-291039-A) are reported. Also, the lipase inhibitory effect of grape seed extract (Nutrition 2003; vol. 19, (10), 876-879), the lipase inhibitory effect and anti-obesity effect of polyphenol from Salacia exhibited in rats (J. Nutr. 2002, 132, 1819-1824), the anti-obesity effect of oolong tea extract exhibited in rats (Int. J. Obes. 1999, 23 98-105), and others are known.
However, reported lipase inhibitory agents from the plants mentioned above are not sufficiently effective. For instance, since they originate from natural sources, there is a problem in maintaining stable lipase inhibitory activity when the content of the active ingredient in the plant is not clearly known. Moreover, use of an inhibitory agent derived from plants with less preference will raise a flavor problem when used in foods and/or beverages. For example, reports on lipid-improving effect of oolong tea are: significant decrease in blood triglyceride levels after drinking 1330 ml/day of commercial oolong tea for 6 weeks [Nihon Eiyou Shokuryou Gakkai-shi (Journal of Japanese society of Nutrition and food science.) 1991; 44(4): 251-259]; and oral administration of oolong tea (2 g×4/day) for 6 consecutive weeks to 102 males and females with simple obesity resulted in more than 1 kg weight loss in 67% of the subjects and significant improvement in the subjects with high blood triglyceride levels after taking oolong tea [Nihon Rinsho Eiyou Gakkai-shi (The Japanese Society of Clinical Nutrition Magazine) 1998; 20(1): 83-90]. These reports show that although drinking a large quantity of oolong tea is recognized to be effective, it is difficult in daily life to continue drinking such large quantities of a drink such as oolong tea. Further, simply providing concentrated oolong tea is not an appropriate and a practical option, due to its strong bitterness and astringency and increased caffeine content.
On the other hand, tea-derived tannins have been reported to have antioxidant activity (Biosci. Biotechnol. Biochem. 2003; 67(2): 396-401), and plant-derived tannins, especially tellimagrandin, have been reported to have not only antioxidant activity (Phytochemistry 1993; 33(3): 557-561) but also antibacterial properties (Microbiol. Immunol. 2004; 48(1): 67-73), anticancer properties (Toxicology Letters 2004; 147(2): 109-119); and to function as a cytokine release regulators (JP 2004-510688-A), etc.
Patent Documents
1. JP Shou 60-11912-B
2. JP Hei 8-259557-A
3. JP Hei 3-228664-A
4. JP Hei 3-219872-A
5. JP Hei 7-61927-A
6. JP Hei 1-102022-A
7. JP Hei 9-40689-A
8. JP Hei 9-291039-A
9. JP 2004-510688-A
Non Patent Documents
1. Summary of 1999 National Nutrition Survey in Japan by The Ministry of Health, Labor and Welfare
2. Rinsho Eiyo (Clinical nutrition) 2001; 98(5): 577-588
3. Rinsyo Hyouka (Clinical evaluation), 1985; 13(2):
4. Rinsyo Hyouka (Clinical evaluation), 1985; 13(2):
5. Lancet 1998; 352:67-172
6. J. Nutr. 1988; 128: 56-60
7. Nihon Eiyou Shokuryou Gakkai-shi (Journal of Japanese society of Nutrition and Food Science) 1999; 52(2): 71-77
8. Kenkou Eiyou Shokuhin Kenkyu (Health food and nutrition food Research) 2002; 5(3): 131-144
9. J. Am. Coll. Nutr. 2000; 19(6): 789-796
10. Clin. Chim. Acta. 2001; 11(2): 109-117
11. Nutrition 2003; vol. 19, (10), 876-879
12. J. Nutr. 2002; 132, 1819-1824
13. Int. J. Obes. 1999; 23 98-105
14. Nihon Eiyou Shokuryou Gakkai-shi (Journal of Japanese society of Nutrition and food science) 1991; 44(4): 251-259
15. Nihon Rinsho Eiyou Gakkai-shi (The Japanese Society of Clinical Nutrition Magazine) 1998; 20(1): 83-90
16. Biosci. Biotechnol. Biochem. 2003; 67(2): 396-401
17. Phytochemistry 1993; 33(3): 557-561
18. Microbiol. Immunol. 2004; 48(1): 67-73
19. Toxicology Letters 2004; 147(2): 109-119